In a disc brake device, a piston is movably supported to a cylinder portion of a caliper, friction pads are operable to push a disc rotor as the piston moving frontward during pressurization, a seal mechanism arranged at the cylinder portion is operable to return the piston to an initial position during depressurization, and the seal mechanism is constituted with a movable element arranged between the cylinder portion and the piston (15) as being movable frontward in the same direction of the piston, a first seal member elastically arranged between the piston and the movable element to make the movable element accompany the piston, a low elasticity member being compressively deformable with initial pressurization of the piston via the movable element, and a high elasticity member being compressively deformable with pressurization of the piston via the movable element.