An interleukin-1 receptor subtype that competes with the $INTERLEUKIN-$1 RECEPTOR TYPE I for binding to $INTERLEUKIN-$1ALPHA and $INTERLEUKIN-$1BETA. The interleukin-1 type II receptor appears to lack signal transduction capability. Therefore it may act as a "decoy" receptor that modulates the activity of its ligands. Both membrane-bound and soluble forms of the receptor have been identified.