An image forming apparatus, comprising: a printing unit configured to perform normal printing of a job according to a setting; an acceptance unit configured to accept a request for executing printing of another job while the printing unit is performing the normal printing of the job according to the setting; a printing control unit configured to, when the request for executing printing of another job is a request for executing trial printing of a succeeding job, control the printing unit to interrupt the normal printing of the job to perform the trial printing of the succeeding job, the succeeding job being to be performed later than the job which is a preceding job and being different from the preceding job; a stacker having a stacker tray; and a sheet ejection control unit configured to control an ejection unit to discharge a recording medium printed in the normal printing of the job and a recording medium printed in the trial printing of the succeeding job to the stacker, characterized in that the stacker further comprises a sample tray, the image forming apparatus is configured to perform the trial printing of the succeeding job interrupting in the normal printing of the preceding job, so that the job setting and trial printing of the succeeding job can be completed before the normal printing of the preceding job is completed, and that the sheet ejection control unit is configured to control the ejection unit to discharge the recording medium printed in the normal printing of the preceding job on the stacker tray of the stacker, and to discharge the recording medium printed in the trial printing of the succeeding job on the sample tray of the stacker, wherein the printing unit is configured to perform the normal printing consecutively, wherein when the request for executing printing of another job accepted at the acceptance unit is not a request for executing trial printing of the succeeding job, the printing control unit is configured to store the execution request for the normal printing of the succeeding job, so that the normal printing of the succeeding job is started after the completion of the normal printing of the preceding job. a printing unit configured to perform normal printing of a job according to a setting; an acceptance unit configured to accept a request for executing printing of another job while the printing unit is performing the normal printing of the job according to the setting; a printing control unit configured to, when the request for executing printing of another job is a request for executing trial printing of a succeeding job, control the printing unit to interrupt the normal printing of the job to perform the trial printing of the succeeding job, the succeeding job being to be performed later than the job which is a preceding job and being different from the preceding job; a stacker having a stacker tray; and a sheet ejection control unit configured to control an ejection unit to discharge a recording medium printed in the normal printing of the job and a recording medium printed in the trial printing of the succeeding job to the stacker, characterized in that the stacker further comprises a sample tray, the image forming apparatus is configured to perform the trial printing of the succeeding job interrupting in the normal printing of the preceding job, so that the job setting and trial printing of the succeeding job can be completed before the normal printing of the preceding job is completed, and that the sheet ejection control unit is configured to control the ejection unit to discharge the recording medium printed in the normal printing of the preceding job on the stacker tray of the stacker, and to discharge the recording medium printed in the trial printing of the succeeding job on the sample tray of the stacker, wherein the printing unit is configured to perform the normal printing consecutively, wherein when the request for executing printing of another job accepted at the acceptance unit is not a request for executing trial printing of the succeeding job, the printing control unit is configured to store the execution request for the normal printing of the succeeding job, so that the normal printing of the succeeding job is started after the completion of the normal printing of the preceding job.