An inhaler comprising: a detachable heating unit; a power supply; a case; a chassis accommodated in an internal space of the case; a plurality of magnets arranged with a gap therebetween and held by the chassis; an inner member covering a side surface of the chassis; and an outer member covering an outer surface of the inner member, wherein the outer member is replaceably fixed to the case by said plurality of magnets held by the chassis so as to cover an outer surface of the inner member, wherein the chassis includes a chassis main body holding the plurality of magnets, and a plate-shaped dividing wall perpendicular to the chassis main body and extending in a longer direction of the chassis main body, wherein the power supply is accommodated in a power supply accommodation space defined by the case and the dividing wall, the inhaler further comprising: a heating unit accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the heating unit is detachably accommodated in the heating unit accommodation region, and the inhaler further comprising: a micro controller unit, MCU,; an MCU-mounted board mounting the MCU; and a board accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the MCU-mounted board is accommodated in the board accommodation region. a detachable heating unit; a power supply; a case; a chassis accommodated in an internal space of the case; a plurality of magnets arranged with a gap therebetween and held by the chassis; an inner member covering a side surface of the chassis; and an outer member covering an outer surface of the inner member, wherein the outer member is replaceably fixed to the case by said plurality of magnets held by the chassis so as to cover an outer surface of the inner member, wherein the chassis includes a chassis main body holding the plurality of magnets, and a plate-shaped dividing wall perpendicular to the chassis main body and extending in a longer direction of the chassis main body, wherein the power supply is accommodated in a power supply accommodation space defined by the case and the dividing wall, the inhaler further comprising: a heating unit accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the heating unit is detachably accommodated in the heating unit accommodation region, and the inhaler further comprising: a micro controller unit, MCU,; an MCU-mounted board mounting the MCU; and a board accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the MCU-mounted board is accommodated in the board accommodation region. a heating unit accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the heating unit is detachably accommodated in the heating unit accommodation region, and the inhaler further comprising: a micro controller unit, MCU,; an MCU-mounted board mounting the MCU; and a board accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the MCU-mounted board is accommodated in the board accommodation region. a micro controller unit, MCU,; an MCU-mounted board mounting the MCU; and a board accommodation region defined in a side opposite to the power supply accommodation space with the dividing wall therebetween, wherein the MCU-mounted board is accommodated in the board accommodation region.