noun
A room or space where products are displayed for viewing, often in a commercial or exhibition setting.
新しい家具の陳列室を見に行った。
I went to see the new furniture showroom.
展示室 is a more general term for an exhibition room, while 陳列室 often implies a commercial showroom where items are arranged for sale or display.
Compound of 陳列 (chinretsu, 'display, exhibition') and 室 (shitsu, 'room').