Maintaining task-relevant information in working memory (WM) while preventing distraction from task-irrelevant information is essential for adaptive behavior. However, whether the task-irrelevant information is removed or retained in WM remains debated. This study addressed this controversy across two experiments employing a retrospectively cueing (retro-cue) paradigm that examined simultaneous influence from endogenous and exogenous factors on internal representations. Behavioral results showed that retro-cues aligning endogenous and exogenous factors enhanced the retention for task-relevant information but negatively impacted memory for task-irrelevant information. Conversely, retro-cues that created conflicts between the two factors improved memory performance for task-irrelevant information whereas sacrificed memory for task-relevant information, in a way similar with retro-cues that merely involved exogenous factors. Results of event-related potentials (ERPs) provided direct evidence for the fate of task-irrelevant WM information via the component of contralateral delayed activity (CDA). ERP results of CDA suggested that task-irrelevant information was dropped out of WM when endogenous and exogenous factors were aligned, but was maintained in WM either when the two factors were in conflicts, or when there was only the exogenous influence. To conclude, this study suggested that task-irrelevant information was saved from being removed out of WM when there were conflicts between endogenous and exogenous factors, in a way similar with that when there was only exogenous influence.