Previous research suggests that perceptual cues such as gazing or waving the hand affords conversation initiation (Trujilo & Holler, 2023). However, few studies have directly examined behavioral evidence supporting the affordance. We hypothesized that if eye-gaze induces conversation as a social affordance without requiring higher-order cognitive processing, then eye-gaze implemented in an artificial agent would facilitate the response. In the experiment, participants sat at a 90° angle to a robot (CommU) on its left side and worked separately at the same desk. They spoke to the robot as soon as they heard the beep sound. Before the sound, the robot repeatedly moved the head and eyes to the left and right with three different angles of perspective depending on the conditions. In the communicative condition, the angle was the same level as the participant, yielding eye gazing. In the other two conditions, the angle was either upper or lower, and it did not gaze at them even when the robot head was directed toward the participant. The sound was made on different timings. As results, the latency from the sound to their speech was significantly shorter when the sound timing was the robot’s directing the head to the left than the right only in the communicative trials. This suggests that eye gaze plays an important role for conversation even with a robot partner. It implies that perceptual information of eye-gaze itself affords conversation initiation.