There is provided a substrate detection apparatus of detecting whether or not a substrate is normally supported by a support part at a predetermined position, in a transfer device including the support part configured to support a plurality of disc-like substrates in multi-stage processing at vertical intervals. The substrate detection apparatus includes: a plurality of optical sensors, each of the plurality of optical sensors including a light transmitting part configured to irradiate a light and a light receiving part configured to receive the light from the light transmitting part, wherein at least one pair of the plurality of optical sensors are disposed such that the light from the light transmitting part is sequentially blocked at each of the plurality of disc-like substrates, during the plurality of disc-like substrates is collectively transferred while being normally supported by the support part at the predetermined positions.