The present invention provides an 8-oxoadenine compound having immunomodulating activities such as an interferon inducing activity and useful as an antiviral agent and antiallergic agent, which is represented by the following formula (1): [wherein the ring A represents a 6-10 membered aromatic carbocyclic ring and the like, R represents a halogen atom, an alkyl group and the like, n represents an integer of 0-2, Z1 represents alkylene, X2 represents oxygen atom, sulfur atom, SO2, NR5, CO, CONR5, NR5CO and the like, Y1, Y2 and Y3 represent independently a single bond or an alkylene group, X1 represents oxygen atom, sulfur atom, NR4 (R4 is hydrogen atom or an alkyl group) or a single bond, R2 represents a substituted or unsubstituted alkyl group, R1 represents hydrogen atom, hydroxy group, an alkoxy group, an alkoxycarbonyl group or a haloalkyl group] or its pharmaceutically acceptable salt.