A measurement device with electroencephalography (EEG) and electrocardiography (ECG) functionalities includes a shell and a turning structure. The shell includes a first contact and a second contact located at a first side of the shell; and a third contact. The turning structure, disposed on the shell, is utilized for adjusting the third contact to be located at the first side when the measurement device is in an EEG mode, and adjusting the third contact to be located at a second side of the shell when the measurement device is in an ECG mode, wherein the second side is substantially opposite to the first side.