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.