An IOL injection instrument (1) comprising: a lens holding part (10) including: a setting part (12) having a lens set position on which an intraocular lens (40) is placed and a lens standby position provided forward of the lens set position and a cylindrical injection part (11) coupled to the setting part to feed the lens placed on the setting part from a tip end a main unit (20) having a cylindrical configuration provided with the lens holding part at a front end and a plunger (30) provided to be movable forward and backward in an axis direction in a cylinder of the main unit to push the lens out of the lens holding part, characterized in that the main unit includes a centering portion (60) internally fixedly formed therein to prevent axis deflection of the plunger, the centering portion having a fitting part (61) having almost the same diameter as that of the plunger (31), and the centering portion being fittable to the plunger during a moving operation of the plunger to center the plunger, the plunger is formed of such a material and with such a diameter as to produce a restoring force capable of correcting displacement and a bent state of the lens against the friction force caused by contact between the lens placed in the lens standby position and the inner wall of the lens holding part in order to prevent the plunger from bending in a position forward of the centering portion and deflecting an axis by displacement of the lens when the lens is moved from the lens set position to the lens standby position during the moving operation.
