The invention provides a movable contact member of which the stroke can be increased without shortening the life of the movable contact member and which makes a switch device using the movable contact member small, and a switch device using the movable contact member. A movable contact member (1) includes a swelling portion (11) that swells in the shape of a dome and can operates reverselywhen pressed, and a skirt portion (12) that is continuously formed from an outer peripheral edge portion (11a) of the swelling portion (11). The skirt portion (12) includes cut-out portions (32) cut out at four portions thereof, portions of the skirt portion (12) except for the cut-out portions (32) form contact portions (52), the cut-out portions (32) of the skirt portion (12) swell toward the swelling portion (11) so that portions of the skirt portion (12) except for the cut-out portions (32) form portions capable of being grounded, and a cut-out face shape (PS) of each of the cut-out portions (32) is a linear shape or a gently curved shape when the skirt portion (12) does not swell. Further, a switch device (201) is formed using the movable contact member (1).