An intraocular lens insertion device comprising: a tube shaped device main unit arranged in which is set an intraocular lens having a pair of haptics (20a, 20b) projecting from an optical portion; a plunger (16, 106, 110, 112, 114, 118, 124) adapted to be inserted into the device main unit from a back side in an axial direction thereof and attached to the device main unit; a stage arranged on which the intraocular lens is set being provided in an intermediate part of the axial direction of the device main unit; and a tapered insertion tube part formed facing a front side in the axial direction from the stage so that the intraocular lens set on the stage is able to be inserted into an eye by being moved in an axial forward direction of the device main unit by the plunger (16, 106, 110, 112, 114, 118, 124) and by being transformed to be smaller and extruded through the insertion tube part, wherein: the intraocular lens is set on the stage with the pair of haptics (20a, 20b) extending from the optical portion facing forward and backward in the axial direction of the device main unit, characterized in that the stage has a deformation guide member (76, 78) arranged to deform the optical portion to a curved shape which becomes convex facing an outer peripheral side of the insertion tube part as it is moved forward, in use, in the axial forward direction by movement of the plunger (16, 106, 110, 112, 114, 118, 124) in the axial forward direction of the main unit, a tip part of the plunger (16, 106, 110, 112, 114, 118, 124) that is adapted to press the intraocular lens includes an optical portion pressing surface (88, 122, 126) configured to press the optical portion, a haptic pressing surface (90, 126) configured to press the haptic extending from the optical portion in an axial backward direction of the device main unit, and an engaging part (86, 120, 126) configured to be engaged with the haptic pressed by the haptic pressing surface (90, 126) so as to suppress displacement of the haptic to a side for which the optical portion is curved and deformed to be convex and so as to enter the haptic into a concave side of the optical portion. a tube shaped device main unit arranged in which is set an intraocular lens having a pair of haptics (20a, 20b) projecting from an optical portion; a plunger (16, 106, 110, 112, 114, 118, 124) adapted to be inserted into the device main unit from a back side in an axial direction thereof and attached to the device main unit; a stage arranged on which the intraocular lens is set being provided in an intermediate part of the axial direction of the device main unit; and a tapered insertion tube part formed facing a front side in the axial direction from the stage so that the intraocular lens set on the stage is able to be inserted into an eye by being moved in an axial forward direction of the device main unit by the plunger (16, 106, 110, 112, 114, 118, 124) and by being transformed to be smaller and extruded through the insertion tube part, wherein: the intraocular lens is set on the stage with the pair of haptics (20a, 20b) extending from the optical portion facing forward and backward in the axial direction of the device main unit, characterized in that the stage has a deformation guide member (76, 78) arranged to deform the optical portion to a curved shape which becomes convex facing an outer peripheral side of the insertion tube part as it is moved forward, in use, in the axial forward direction by movement of the plunger (16, 106, 110, 112, 114, 118, 124) in the axial forward direction of the main unit, a tip part of the plunger (16, 106, 110, 112, 114, 118, 124) that is adapted to press the intraocular lens includes an optical portion pressing surface (88, 122, 126) configured to press the optical portion, a haptic pressing surface (90, 126) configured to press the haptic extending from the optical portion in an axial backward direction of the device main unit, and an engaging part (86, 120, 126) configured to be engaged with the haptic pressed by the haptic pressing surface (90, 126) so as to suppress displacement of the haptic to a side for which the optical portion is curved and deformed to be convex and so as to enter the haptic into a concave side of the optical portion. the intraocular lens is set on the stage with the pair of haptics (20a, 20b) extending from the optical portion facing forward and backward in the axial direction of the device main unit, characterized in that the stage has a deformation guide member (76, 78) arranged to deform the optical portion to a curved shape which becomes convex facing an outer peripheral side of the insertion tube part as it is moved forward, in use, in the axial forward direction by movement of the plunger (16, 106, 110, 112, 114, 118, 124) in the axial forward direction of the main unit, a tip part of the plunger (16, 106, 110, 112, 114, 118, 124) that is adapted to press the intraocular lens includes an optical portion pressing surface (88, 122, 126) configured to press the optical portion, a haptic pressing surface (90, 126) configured to press the haptic extending from the optical portion in an axial backward direction of the device main unit, and an engaging part (86, 120, 126) configured to be engaged with the haptic pressed by the haptic pressing surface (90, 126) so as to suppress displacement of the haptic to a side for which the optical portion is curved and deformed to be convex and so as to enter the haptic into a concave side of the optical portion.