A drug solution delivery apparatus comprising: a pump main body in which a drive unit is provided; a cartridge main body detachably mounted on the pump main body; and a control unit configured to control the drive unit, wherein the cartridge main body includes a drug solution storage unit filled with a drug solution, a plunger member configured to push out the drug solution filled in the drug solution storage unit, and a plunger operation unit configured to operate movement of the plunger member, the plunger operation unit includes a feed screw shaft configured to be rotated by the drive unit, an axial direction of the feed screw shaft being parallel to a moving direction of the plunger member, characterized in that a slide nut is provided and configured to be screwed to the feed screw shaft to be movable along the axial direction of the feed screw shaft, and to be interlocked with the plunger member, and a rib is provided on a side opposite to a side on which the slide nut approaches the plunger member and configured to restrict movement of the slide nut, at least one of the pump main body and the cartridge main body is provided with an attachment detection sensor configured to detect that the slide nut attaches to the rib, and when the cartridge main body is mounted on the pump main body, the control unit causes the drive unit to rotate in a direction opposite to a forward direction in which the slide nut is interlocked with the plunger member, and determines whether the cartridge main body is new or has been used based on a detection signal of the attachment detection sensor, in the new cartridge main body, the slide nut is disposed at a predetermined interval from the rib, and when the cartridge main body is mounted on the pump main body, the control unit causes the drive unit to rotate in a reverse direction by a predetermined amount, the number of rotations by which the drive unit is caused to rotate is set to be equal to or greater than the number of rotations of the drive unit until the slide nut attaches to the rib, and the number of rotations of the drive unit until the slide nut attaches to the rib to restrict the reverse movement is evaluated in order to determine whether the cartridge main body is new or has been used. a pump main body in which a drive unit is provided; a cartridge main body detachably mounted on the pump main body; and a control unit configured to control the drive unit, wherein the cartridge main body includes a drug solution storage unit filled with a drug solution, a plunger member configured to push out the drug solution filled in the drug solution storage unit, and a plunger operation unit configured to operate movement of the plunger member, a drug solution storage unit filled with a drug solution, a plunger member configured to push out the drug solution filled in the drug solution storage unit, and a plunger operation unit configured to operate movement of the plunger member, the plunger operation unit includes a feed screw shaft configured to be rotated by the drive unit, an axial direction of the feed screw shaft being parallel to a moving direction of the plunger member, characterized in that a slide nut is provided and configured to be screwed to the feed screw shaft to be movable along the axial direction of the feed screw shaft, and to be interlocked with the plunger member, and a rib is provided on a side opposite to a side on which the slide nut approaches the plunger member and configured to restrict movement of the slide nut, at least one of the pump main body and the cartridge main body is provided with an attachment detection sensor configured to detect that the slide nut attaches to the rib, and when the cartridge main body is mounted on the pump main body, the control unit causes the drive unit to rotate in a direction opposite to a forward direction in which the slide nut is interlocked with the plunger member, and determines whether the cartridge main body is new or has been used based on a detection signal of the attachment detection sensor, in the new cartridge main body, the slide nut is disposed at a predetermined interval from the rib, and when the cartridge main body is mounted on the pump main body, the control unit causes the drive unit to rotate in a reverse direction by a predetermined amount, the number of rotations by which the drive unit is caused to rotate is set to be equal to or greater than the number of rotations of the drive unit until the slide nut attaches to the rib, and the number of rotations of the drive unit until the slide nut attaches to the rib to restrict the reverse movement is evaluated in order to determine whether the cartridge main body is new or has been used.