An inhaler comprising: a detachable heating unit ; a power supply (BAT); 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 (BAT) 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 (BAT); 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 (BAT) 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 . <EOS>