A damper device, comprising: - a coil spring (31, 32) interposed in a circumferential direction between a first rotating body and a second rotating body, in which two ends thereof are supported to the rotating bodies (1, 2), orienting a direction along a spring central axis (Sc), which is a center of winding, toward the circumferential direction; and - a spring seat (41, 42) made of resin which is attached to the rotating bodies (1, 2), in a state in which the two ends of the coil spring (31, 32) are supported in the direction along the spring central axis (Sc); wherein: - the spring seat (41, 42) comprises: - a seat portion having a spring seating surface on which the ends of the coil spring (31, 32) are seated in the direction along the spring central axis (Sc), - an overhang portion which is extended from a device outer diameter direction end of the rotating body (1, 2) in the seat portion in the circumferential direction and covers the device outer diameter direction of the coil spring (31, 32), and - a pair of clamping protrusions (46, 47) that protrude from the seat portion, that are spaced apart from each other in the device axial direction (Ce) so as to be capable of sandwiching an attaching portion (11b, 24b) of rotating body (1, 2) in the device axial direction (Ce), and that are attached to the attaching portion (11b, 24b) so as to be relatively turnable in the radial direction of a rotating body (1, 2), characterized in that, - the pair of clamping protrusions (46, 47) includes a low-rigidity portion on an outer diameter direction side of the spring central axis (Sc) and having a first rigidity, and a high-rigidity portion on an inner diameter direction side of the spring central axis (Sc) and having a second rigidity that is higher than the first rigidity. - a coil spring (31, 32) interposed in a circumferential direction between a first rotating body and a second rotating body, in which two ends thereof are supported to the rotating bodies (1, 2), orienting a direction along a spring central axis (Sc), which is a center of winding, toward the circumferential direction; and - a spring seat (41, 42) made of resin which is attached to the rotating bodies (1, 2), in a state in which the two ends of the coil spring (31, 32) are supported in the direction along the spring central axis (Sc); - the spring seat (41, 42) comprises: - a seat portion having a spring seating surface on which the ends of the coil spring (31, 32) are seated in the direction along the spring central axis (Sc), - an overhang portion which is extended from a device outer diameter direction end of the rotating body (1, 2) in the seat portion in the circumferential direction and covers the device outer diameter direction of the coil spring (31, 32), and - a pair of clamping protrusions (46, 47) that protrude from the seat portion, that are spaced apart from each other in the device axial direction (Ce) so as to be capable of sandwiching an attaching portion (11b, 24b) of rotating body (1, 2) in the device axial direction (Ce), and that are attached to the attaching portion (11b, 24b) so as to be relatively turnable in the radial direction of a rotating body (1, 2), characterized in that, - a seat portion having a spring seating surface on which the ends of the coil spring (31, 32) are seated in the direction along the spring central axis (Sc), - an overhang portion which is extended from a device outer diameter direction end of the rotating body (1, 2) in the seat portion in the circumferential direction and covers the device outer diameter direction of the coil spring (31, 32), and - a pair of clamping protrusions (46, 47) that protrude from the seat portion, that are spaced apart from each other in the device axial direction (Ce) so as to be capable of sandwiching an attaching portion (11b, 24b) of rotating body (1, 2) in the device axial direction (Ce), and that are attached to the attaching portion (11b, 24b) so as to be relatively turnable in the radial direction of a rotating body (1, 2), characterized in that, - the pair of clamping protrusions (46, 47) includes a low-rigidity portion on an outer diameter direction side of the spring central axis (Sc) and having a first rigidity, and a high-rigidity portion on an inner diameter direction side of the spring central axis (Sc) and having a second rigidity that is higher than the first rigidity.