An endoscope includes an insertion portion having a light source portion configured to emit illuminating light therefrom when inserted into a body cavity. An imaging portion is configured to capture an image in the body cavity. A transmission portion configured to transmit the image captured by the imaging portion. A battery is configured to supply electric power needed for endoscopic observation. A power control portion is configured to selectively control a supply of electric power to all of the light source portion, the imaging portion, and the transmission portion in a standby mode in which power consumption is reduced compared with a normal operation mode in which a supply of electric power is performed from the battery to all of the light source portion, the imaging portion, and the transmission portion.
