Disclosed herein are a three-way authentication apparatus and method in a cloud environment. The three-way authentication method in a cloud environment includes performing, by a control device and a service device, mutual authentication through an IF-1 interface, performing, by the control device and a function server, mutual authentication through an IF-2 interface, requesting, by the control device, the function server to issue an authentication token for authentication between the service device and the function server, and delivering an authentication token issued by the function server to the service device, and performing, by the service device, mutual authentication with the function server using the delivered authentication token through an IF-3 interface.