a weight average molecular weight mw of from 1000 to 6000 concretely including arufon up 1000 up 1010 up 1021 up 1061 up 1080 up 1190 all trade names by toa gosei actflow umb 1001 ume 1001 umm 1001 all trade names by soken chemical amp engineering etc one or more of these may be used either singly or as combined preferably the liquid acrylic polymer has a viscosity of from 300 to 11 000 mpa u00b7 s 25 u00b0 c more preferably from 300 to 5 000 even more preferably from 300 to 2 000 when the viscosity of the liquid acrylic polymer is too high then the handlability thereof in kneading and stirring may be poor and the shapability thereof may also be poor regarding the amount of the liquid acrylic polymer in the eraser of the invention the liquid acrylic polymer preferably accounts for from 20 to 200 parts by mass relative to 100 parts by mass of the base resin more preferably from 50 to 180 parts by mass when the amount of the liquid acrylic polymer is less than 20 parts by mass then the eraser may be hard and its elasticity may lower and its erasability may be poor but on the other hand when the amount is more.