A sheet detection device includes, as detection pieces, a first detection piece integrally provided on a rotary shaft and a second detection piece attached to the first detection piece via a biasing member. The second detection piece is capable of rotation in conjunction with the first detection piece under a biasing force of the biasing member. When the second detection piece is brought into contact with a ceiling at an upper part of the rotary shaft, the second detection piece stops further rotation while the first detection piece is capable of rotation together with the rotary shaft against the biasing force.