Provided is a method for performing wireless communication by a first device, the method comprising the steps of: setting an actual bandwidth part (BWP) associated with the first device; setting an initial BWP associated with the first device; and setting a sidelink (SL) BWP associated with SL communication of the first device, wherein the SL communication is deactivated on the basis of the numerology of the actual BWP and the numerology of the SL BWP being the same, the numerology of the initial BWP being different from the numerology of the SL BWP, and the first device switching between the SL BWP and the initial BWP.