The present invention relates to a body insertable device having an adjustable radiation emission direction, comprising: an outer body including a first outer body extending in a long manner, a second outer body extending in a long manner, and a bent part for connecting the first outer body and the second outer body such that the first outer body and the second outer body are bent; a first inner body positioned inside the first outer body and having an accommodation space in which a radiation source is accommodated; a second inner body, which is positioned inside the second outer body, has a guide space enabling the radiation source to pass therethrough, and can operate the rotation thereof; and an inner connection part, which is positioned in correspondence to the bent part inside the outer body, has a connection space communicating with a guide space and the accommodation space such that the radiation source can pass therethrough, and connects the first inner body and the second inner body, wherein the first inner body is separated from the first outer body and rotated by the rotation of the second inner body.