Indoor unit and air-conditioning apparatus

An indoor unit comprising:

• an air-sending device from which air is taken into a body;
• a securing plate provided at an upper edge of a sidewall of a drain pan for collecting drain water generated from a heat exchanger through which the air blown by the air-sending device passes;
• and
• an antimicrobial-agent-containing case that contains an antimicrobial agent and includes
• a container portion positioned in an area where the drain water is collected,
• a case-attaching portion conforming to the securing plate and being detachably attached to the securing plate, and
• an arm connecting the container portion and the case-attaching portion,
• wherein:
• the antimicrobial-agent-containing case is attachable to the securing plate from an opening of the drain pan facing the air-sending device;
• the securing plate has an attaching hole;
• an attaching space having a recessed shape is provided below the securing plate;
• a tab portion is provided below the case-attaching portion of the antimicrobial-agent-containing case;
• and
• the antimicrobial-agent-containing case is fixed to the drain pan at a position where the tab portion which is inserted into the attaching hole is visible from the attaching space.