A watch type mobile terminal which is worn on a wrist includes: a main body having a display unit; a band unit connected to the main body such that the mobile terminal is worn on the wrist, and surround the wrist; a sensor unit installed in a region of the main body, having a light emitting unit and a light receiving unit, and configured to collect biometric information; a deformation unit formed in a region of the band unit facing the wrist, and provided to be deformed in shape; and a control unit configured to control the deformation unit to be deformed based on activation of the sensor unit.