A small-sized onboard device that includes a speaker and a microphone and is configured to reduce noise caused by an echo is provided. The speaker is provided inside a housing that forms a cavity inside so that a sound emission surface of the speaker faces a direction substantially orthogonal to a front surface, and a first opening is formed in a front surface of the housing. A microphone case and a sound guide member are juxtaposed on the front surface of the housing. A microphone is housed inside the microphone case. The microphone case has a sound pickup hole in a front surface of the microphone case. The sound guide member has a sound guide hole that passes through the sound guide member. The first opening is provided in a vicinity of a top surface or a bottom surface of the housing.