A master apparatus for a master slave apparatus, the master apparatus controlling a slave apparatus, the master apparatus including a hand operation mechanism configured to be operated by a person for opening and closing a hand mechanism including a pair of opening and closing members, the hand mechanism being connected to a slave mechanism, the slave apparatus including the slave mechanism and the hand mechanism. The hand operation mechanism includes a fixed unit, an opening and closing operation unit, and a slide unit. The opening and closing operation unit is connected to the slide unit, is capable of reciprocating with respect to the fixed unit, and is openable and closable with respect to the fixed unit. The master hand controlling device controls opening and closing of the pair of opening and closing members on the basis of an opening and closing amount of the opening and closing operation unit.