The present invention provides a communication method for realizing a function for URLLC that requires high-reliability and/or low-latency communication in a 5GS. A user apparatus can provide a communications method capable of realizing a URLLC function in a 5GS by performing the communication method, which comprises: receiving, in a registration procedure, a registration accept messages including DNN and S-NSSAI for URLLC; receiving, in a first PDU session establishment procedure, a PDU session establishment accept messages including information indicating that an SSC mode for a PDU session for URLLC is SSC mode 1; and transmitting, in a second PDU session establishment procedure, a PDU session establishment request messages including information indicating that the SSC mode for the PDU session for URLLC is SSC mode 1.