The present invention provides a carbon nanomaterial production apparatus 1 that includes a reaction tube 2 into which raw material gas and carrier gas are supplied and accordingly in which carbon nanomaterial is grown, a connection tube 4 that is connected to the reaction tube 2 and through which an aerosol-like mixture of the carbon nanomaterial and the carrier gas passes, and a collection tube 3 that is connected to the connection tube 4 and collects the carbon nanomaterial from the mixture. The collection tube 3 includes a discharge section 32 that is located above a junction 33 with the connection tube 4 and discharges the carrier gas contained in the mixture to outside, and a trapping section 31 that is located below the junction 33 with the connection tube 4 and traps the carbon nanomaterial that is separated from the mixture by gravitational sedimentation.