Provided is an insert capable of detecting the tip of an insert such as a puncture needle with high sensitivity, and a photoacoustic measurement device provided with the insert. A puncture needle body 15a having an opening 15b at the distal end, at least a distal end portion of which is formed in a hollow shape to be inserted into the subject, and a hollow portion 15c of the puncture needle main body 15a, which extends in the longitudinal direction of the puncture needle main body 15a. Along the optical fiber 14 provided along the puncture needle main body 15a, the optical fiber 14 is provided at the light emitting end 14a of the optical fiber 14, and absorbs light emitted from the light emitting end 14a to generate a photoacoustic wave. And a photoacoustic wave generating unit 16 that generates the light, and the surface roughness of the light emitting end 14a of the optical fiber 14 is larger than the surface roughness of the light incident end of the optical fiber.穿刺針などの挿入物の先端を感度良く検出することができる挿入物およびその挿入物を備えた光音響計測装置を提供する。 先端に開口１５ｂを有し、少なくとも先端部分が被検体内に挿入される中空状に形成された穿刺針本体１５ａと、穿刺針本体１５ａの中空部１５ｃに、穿刺針本体１５ａの長さ方向に沿って設けられた光ファイバ１４と、穿刺針本体１５ａの先端側に配置される光ファイバ１４の光出射端１４ａに設けられ、その光出射端１４ａから出射される光を吸収して光音響波を発生する光音響波発生部１６とを備え、光ファイバ１４の光出射端１４ａの表面粗さが、光ファイバの光入射端の表面粗さよりも粗い。
