A user apparatus communicates with a base station apparatus via a radio frame. The user apparatus includes a reception unit configured to receive information related to a RACH configuration table that indicates allocation of RACH resources in the time domain in the radio frame and information used for excluding unavailable RACH resources of the radio frame in the time domain, a control unit configured to identify available RACH resources based on the information related to the RACH configuration table and the information used for excluding unavailable RACH resources, and a transmission unit configured to transmit a preamble to the base station apparatus by using the identified available RACH resources.