An image forming apparatus includes a main body and a replaceable component. The main body includes a first storage unit storing first authentication informations for authentication with the replaceable component, a data storage unit storing authentication data for choosing the first authentication information. The replaceable component includes a second storage unit storing second authentication informations corresponding to the first authentication information. Authentication data is set to be different among different image forming apparatuses. The main body attempts authentication with the replaceable component using the first authentication information chosen based on the authentication data. When the second authentication information corresponding to the chosen first authentication information is stored, a control unit establishes connection between communication units of the main body and the replaceable component.