To provide an opening and closing window provided with a frame body used for both an operator handle specification and a cam latch specification.

The frame body 1 having a resin frame disposed on the indoor side of a metallic frame includes a sliding door 2 openably and closably fitted to the inside thereof. A lower frame 20 constituting the frame body 1 has a protruding part 25 protruding to the indoor side, and a metallic lower frame 21 constituting the lower frame 20 has an upper surface part 25c constituting the upper surface of the protruding part 25. The upper surface part 25c is formed in a planar shape, so that an opening and closing device mount piece 50 vertically raised to the upper surface is mountable thereon.