fig5 the matching operation of the present embodiment is almost the same as that of the prior art now for example assuming for example that the stored data is 34 1 34 first in the cycle t1 the cam cells are set in an initial state whereby the match line 10 is precharged to the 34 h 34 level to be in the floating cell in the cycle t2 the retrieval data is applied to the bit line pair 6 and 7 in case the stored data and the retrieval data do not match with each other the match line 10 is discharged to the 34 l 34 level on the other hand in case the stored data and the retrieval data match with each other the match line 10 is not discharged to be maintained at the 34 h 34 level in fig5 the solid line shows a case in which the data of 34 1 34 is applied to the bit line pair 6 and 7 and the broken line shows a case in which the data of 34 0 34 is applied thereto referring to fig6 the reading operation is almost the same as that of the prior art it is assumed herein that the stored data is 34 1 34 first in the cycle t1 the cam cells are set in the initial state in the cycle t2 the match line 10 the bit line 6 and the inversion bit line 7 are discharged to the 34 l 34 level and further more the bit line 6 and the inversion bit line 7 are caused to enter the floating state as a result.