An industrial robot includes a first member, a positioning member arranged to be attached to the first member, a second member arranged to rotate relative to the first member, and a first joint for coupling the first member with the second member. The second member has a contact point arranged to contact the positioning member. An indication for requesting to enable the positioning member to contact the contact point is displayed. The second member rotates at the first joint relatively to the first member while the positioning member can contact the contact point. It is detected whether or not the contact point of the second member contacts the positioning member. A position of the second member is stored as an origin when it is detected that the contact point of the second member contacts the positioning member. This method prevents a possible failure of the attaching of the positioning member, and decreases a work load on an operator.