Method and apparatus for transmitting or receiving control channel in communication system

A method of a base station, the method comprising:

• transmitting configuration information for a first search space set and a second search space set to a terminal;
• transmitting first downlink control information (DCI) to the terminal in the first search space set;
• performing a switching operation from the first search space set to the second search space set based on a first slot according to indication information included in the first DCI;
• and
• transmitting second DCI to the terminal through the second search space set from the first slot,
• wherein the first slot is after a slot in which the first DCI is transmitted.

A terminal comprising:

• at least one processor,
• wherein the at least one processor causes the terminal to:
• receive configuration information for a first search space set and a second search space set from a base station;
• receive downlink control information (DCI) from the base station by performing a first physical downlink control channel (PDCCH) monitoring operation in the first search space set;
• perform a switching operation from the first search space set to the second search space set based on a first slot according to indication information included in the DCI;
• and
• perform a second PDCCH monitoring operation in the second search space set from the first slot,
• wherein the first slot is after a slot in which the DCI is received.