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<Extraction> 

The succinic acid aqueous solution was extracted with 10% hydrated MEK in the same method as that in Refer› ential Example 2. In the mixer-settler, 10% hydrated MEK in an amount of 0.5 weight times the succinic acid aqueous solution was fed at a rate of 20 g/min and 10 g/min, respectively. The recovered intermediate phase was sub› jected to pressure filtration, and the raffinate phase was further subjected to countercurrent multi-stage continuous extraction with 10% hydrated MEK in an amount of 1.0 weight time the raffinate phase. As a result, 2,882 g of the extract phase and 1,593 g of the raffinate phase were recovered. A composition thereof is as follows. <Distillation> 

15 Distillation was carried out in the same method as that in Referential Example 2, thereby recovering 438 g of a succinic acid concentrated liquid. A composition thereof is shown in the following Table 7. The analysis of each of the organic acid and the sugar was carried out by means of $_{20 }$ high-performance liquid chromatography under conditions equal to those in Table 2. 

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<Crystallization> 

Crystallization was carried out in the same method as that in Referential Example 2, thereby recovering 113 g of succinic acid and 568 g of a recovered liquid that is a mixed liquid of a crystallization mother liquid and washings. A composition of the resulting succinic acid is shown in the following Table 8, and a composition of the resulting recovered liquid is shown in the following Table 9. The analysis of each of the organic acid and the sugar was carried out by means of high-performance liquid chromatography under conditions equal to those in Table 2. 

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Recovered succinic acid/newly fed succ1mc acid: 113x 0.959/(1,384x0.0865)=91 % 

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<Highly Purification> 

A 30 wt % crude succinic acid aqueous solution was prepared from the above-obtained crude crystal at 80° C., and a chemically activated, powdered activated carbon Dia- hope 8ED (manufactured by Calgon Mitsubishi Chemical Corporation) was then added in an amount of 0.3 wt % relative to the succinic acid. The activated carbon treatment was carried out at 80° C. for 2 hours with stirring at 200 rpm using a three-one motor. 

After filtering out the activated carbon at 80° C., the resulting succinic acid aqueous solution was charged in an SUS 316-made 500-mL induction stirring autoclave and subjected to a hydrogen treatment in the presence of 5% Pd/C (Wako’s catalogue 326-81672, catalyst amount: 0.06 wt % relative to succinic acid) under a condition at a hydrogen pressure of 0.8 MPa at a reaction temperature of 80° C. for a reaction time of 3 hours. As a result, fumaric acid contained in an amount of 1.3% by weight relative to succinic acid in crude succinic acid was entirely derived into succinic acid. After completion of the reaction, the catalyst was filtered out. The hydrogen treatment solution was sub› stantially free from an odor. 

This hydrogen-treated succinic acid aqueous solution was subjected to an ion exchange treatment ( cation exchange resin (Diaion SKlB-H (manufactured by Mitsubishi Chemi› cal Corporation): H type) at 80° C., thereby removing cations having been contained in a trace amount. 

The ion exchange-treated succinic acid aqueous solution was cooled to 20° C. with stirring for about 90 minutes and further kept at 20° C. for one hour to deposit a crystal. The deposited succinic acid was recovered by means of filtration, and the crystal was washed with cold water and then dried in vacuo at 70° C. for 12 hours to obtain white odorless succinic acid (YI=-1). 

In the resulting succinic acid, the concentrations of Na, K, Mg, Ca and NH$_{4 }$ ions were all not more than 1 ppm; the sulfur atom content was less than 1 ppm; and the nitrogen 

