An image pickup apparatus capable of reducing unnecessary reflected light without narrowing an exposure area. A holding member holds a semi-transparent mirror and is rotatably supported by a mirror box so as to move between a mirror-down position in a photographing light path and a mirror-up position out of the photographing light path. A shading member is supported on an object-side end of the holding member via a rotation shaft so as to rotate between a closed position close to the holding member and an opened position apart from the holding member. An urging member energizes the shading member toward the opened position when the holding member is in the mirror-down position. An engagement portion engages with the shading member when the holding member rotates toward the mirror-up position so as to rotate the shading member toward the closed position against the urging force.