A sheet detecting device usable with a sheet feeding device for feeding a sheet, the sheet detecting device includes a common light emitter; a first light receptor and a second light receptor for receiving the light emitted by the common light emitter and output a signal in response to the reception of the light; a first detector configured to detect presence or absence of the sheet by switching the signal outputted by light receptor, in response to the sheet blocking or reflecting the light emitted by the common light emitter; a movable portion capable of being moved by the sheet which is moving; and a second detector configured to detect presence or absence of the sheet by switching the signal outputted by the second light receptor, in response to the movable portion forming or blocking a optical path for the light emitted by the common light emitter.

A printing apparatus includes a container that can accommodate roll paper in which recording paper is wound; a cover for opening and closing the container; a transporter, including a transport motor and a transport roller, that pulls the recording paper from the roll paper and transports the recording paper; a printing section that performs printing on the recording paper at a position facing the transport roller; a first substrate that has a controller controlling the printing section; and a second substrate disposed to intersect the first substrate, in which the transport motor is surrounded by the first substrate, the second substrate, and the container and a shaft of the transport motor is disposed parallel to a shaft of the transport roller.