A planar illumination apparatus according to an embodiment includes a light guide plate, a light source, a frame, a first support member, a first adhesive member, a second support member, and a second adhesive member. The light guide plate has a light extraction surface and a light entering side face. The light source is arranged on the light entering side-face side. The frame has a floor face, and houses the light guide plate and the light source. The first support member supports the light guide plate from the floor face side of the frame. The first adhesive member causes the light guide plate and the first support member to adhere to each other. The second support member supports the light source from the floor face side of the frame. The second adhesive member causes the light source and the second support members to adhere to each other.