It aims to improve the waterproof antifouling by the frame body water meter. Body water meter according to the present invention (100) includes a main body portion formed in a straight line (110), the insertion portion is curved extending from one end of the main body (100) and (120), and, insertion unit (120) is brought into contact with the body surface of the subject, the sensor unit for measuring data related to moisture in the living body (121), a fixed distal end side insertion portion on the distal end surface (122) ( and 120-2), the distal end side insertion portion (120-2) and the base end side insertion portion that supports via a slide mechanism for sliding in a direction substantially perpendicular to the distal end surface (122) and (120-1), the distal end comprising side insertion portion (120-2) and the protective member for covering the sliding mechanism in a liquid tight manner between the proximal end side insertion portion (120-1) (651), a protective member (651), the tip end characterized in that it is configured to smoothly connect the outer circumferential surface of the outer peripheral surface and the base end side insertion portion of the insertion portion (120-2) (120-1).体内水分計の防水性・防汚性を向上させることを目的とする。本発明に係る体内水分計(100)は、直線状に形成された本体部(110)と、本体部(100)の一端から湾曲して延設された挿入部(120)と、を備え、挿入部(120)は、被検者の体表面に接触させることで、生体中の水分に関するデータを測定するセンサ部(121)が、その先端面(122)に固定された先端側挿入部(120-2)と、先端側挿入部(120-2)を、先端面(122)に略直交する方向にスライドさせるスライド機構を介して支持する基端側挿入部(120-1)と、先端側挿入部(120-2)と基端側挿入部(120-1)との間の前記スライド機構を液密に覆う保護部材(651)と、を備え、保護部材(651)は、先端側挿入部(120-2)の外周面と基端側挿入部(120-1)の外周面とを滑らかに接続するように構成されていることを特徴とする。
