The present invention relates to a juicer with simple assembly and disassembly of a housing comprising: a driving portion comprising a motor housing comprising a motor inside, a rotation shaft protruded toward one side of the motor housing and connected to the motor, and a fixed shaft provided at the motor housing so as to be adjacent to the rotation shaft; a juicing portion comprising a roller portion operated by the motor provided at the driving portion so as to pulverize, juice and transfer a juicing material, and a housing for accommodating the roller portion; a fastening portion for detachably joining the housing to the motor housing; and a sensor portion comprising a sensor operation portion provided at the housing, and a sensor provided at the motor housing and operated by a change in distance with the sensor operation portion. There is no need to adjust the location of the fastening portion when the housing is joined to the driving portion, the roller portion and the housing can be easily separated since the sensor portion is provided at the part in which the driving portion is opposite to the housing, an injury due to the operation of the roller portion can be prevented when the housing is separated, and juicing is effective.