A projection apparatus includes a projection module, a network module, a video-audio capturing module, a conference module and a processor. The network module provides a network interface. The video-audio capturing module is configured to capture an image and voice of a local user, and accordingly generates local video-audio data. The conference module provides the video conference function. The processor is electrically connected to the projection module, the network module, the video-audio capturing module and the conference module. When the processor enables the video conference function, the projection apparatus establishes a connection with a remote apparatus through the network interface, in order to receive a remote video-audio data of a remote user from the remote apparatus, and transmit the local video-audio data to the remote apparatus. The projection module projects an image corresponding to the remote video-audio data onto a projection surface.