A sensor device for measuring electroencephalogram (EEG) includes an arm, a sensing portion, a multi-directional joint, a connecting base and a headband component. The arm has a front end and a back end opposite to the front end. The back end of the arm is coupled to the connecting base. The multi-directional joint is disposed on the front end of the arm, and coupled to the sensing portion, so that the sensing portion can rotate relative to the front end of the arm. The headband component includes a plurality of elastic arcuate bands and an anti slip pad coupled to the elastic arcuate bands. The elastic arcuate band has a first side and a second side opposite to the first side. The first side is coupled to the anti slip pad, and the second side is coupled to the connecting base.一種腦波感測裝置,所述腦波感測裝置包括臂體、腦波感測部、萬向關節、連接座以及頭箍組件,其中臂體具有前端以及相對於前端的末端,臂體的末端與連接座相連接,而萬向關節配置於臂體的前端,腦波感測部連接於萬向關節,據以相對前端而轉動。頭箍組件包括多個彈性弧形條以及連接於多個彈性弧形條的止滑墊。每一個彈性弧形條具有第一端部以及相對於第一端部的第二端部,其中第一端部連接止滑墊,第二端部連接於連接座。100‧‧‧腦波感測裝置110‧‧‧腦波感測部120‧‧‧萬向關節130‧‧‧臂體140‧‧‧連接座150‧‧‧頭箍組件152‧‧‧彈性弧形條154‧‧‧T型止滑墊E1‧‧‧第一端部E2‧‧‧第二端部L1‧‧‧連結部L2‧‧‧止滑部P1‧‧‧前端P2‧‧‧末端
