A body-insertable device is introduced into a desired part in a body for injecting a liquid medicine stored in a casing into the desired part. The body-insertable device includes a projecting portion which projects an injection needle injecting the liquid medicine toward the desired part a detecting unit which detects a position relation between a biological tissue surface in the desired part and the injection needle and a control unit. The control unit controls an amount of projection of the injection needle according to the position relation detected by the detecting unit, and controls a puncture depth of the injection needle from the biological tissue surface.
