Provided is a cartridge-type dispenser suitable for extruding viscous materials, wherein a piston does not fall easily out of a cartridge main body and yet is capable of extruding the contents with a smooth action. The cartridge-type dispenser is provided with a cartridge main body (1) that has a filling space (M) for the contents and is equipped with an extrusion nozzle (1a) on the front end thereof, and a piston (2) that is slidably disposed in the filling space (M) of the cartridge main body (1) and extrudes the contents of the filling space (M) from an end of the extrusion nozzle (1a) by application of a push-in force. The piston (2) is configured from a trunk portion (2a) that has an outer circumferential wall that runs along an inner wall of the cartridge main body (1) and is disposed inside the inner circumferential wall of the main body with a gap therebetween, a front end wall portion (2b) that is provided on one end of the trunk portion (2a) and directly contacts the contents of the filling space (M), and a rear end wall portion (2c) that is provided on the other end of the trunk portion (2a) whereon the rod of a push-in tool is pressed to apply the push-in force on the piston (2) itself. On the outer circumferential wall of the trunk portion (2a), protrusions (3) are provided, which contact the inner circumferential wall of the cartridge main body (1). The points of contact form sliding parts of the piston (2) but do not seal the interior of the cartridge main body (1).
