To provide a capsule type medical device capable of stably transmitting image data even when the operation mode of an imaging apparatus is switched while a transmitter is operated.

The capsule type medical device to be fed into a living body in order to observe the inside of the living body includes an imaging means for photographing images inside the living body and a radio communication means for transmitting the image data of the images imaged by the imaging means to the outside of the living body by radio communication. An oscillation circuit provided to the radio communication means has a differential configuration, and an inductor for oscillation disposed between the collector terminals of the oscillation circuit is also used for an antenna for electromagnetic field generation provided to radio communication equipment.