An object of present invention is to easily adjust the puncture depth of an injection needle puncturing a biological tissue in a body and to inject a liquid medicine into the biological tissue to a desired puncture depth. A body-insertable device according to the present invention has a projection mechanism (5) which projects an injection needle (4) injecting a liquid medicine into a desired part in a body toward a biological tissue, an imaging unit (8) which images an image showing the position relation between a biological tissue surface and the injection needle (4), and a control unit (10) which controls driving of the projection mechanism (5) to control the amount of projection of the injection needle (4). The control unit (10) performs image processing which detects the position relation between the injection needle (4) and the biological tissue surface according to the image imaged by the imaging unit (8), controls the amount of projection of the injection needle (4) according to the result of the image processing, and controls the puncture depth of the injection needle (4) from the biological tissue surface.
