To provide a shutter for a camera where two shutter blades rotated simultaneously in a contrary direction are stably actuated at high speed with little frictional resistance and by which the light advancing in a blade chamber is suitably shielded in a closed state.

The blade chamber is constituted between a shutter bottom board 1 and an auxiliary bottom board 2, and the board 1 is on a subject side. An annular part 1i and guide lines 1j, 1k and 1m are formed on the surface of the board 1 on the blade chamber side. Light shielding walls 1n and 1p are formed to surround the annular part 1i, and a light shielding wall 1q is formed on the outside of the wall 1p. The board 2 has nearly symmetric shape, and the annular parts, the guide lines and the light shielding walls of both of them are opposed and the shutter blades 5 and 6 and the auxiliary blade 7 are actuated in-between them. Therefore, the light advancing to an optical axis direction from an outer periphery part direction and reflected on the surfaces of the blades 5 and 6 on a film side so as to reach film in the blade chamber is mostly intercepted by the walls 1n, 1p and 1q in the closed state.