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