Spontaneous mode-switching was investigated for a camphor scraping at an air/water interface. The motion of a camphor scraping intermittently switched between revolution and translation. To clarify the nature of this spontaneous mode-switching, the surface tension at the air/water interface was measured and the diffusion of the camphor layer was visualized. The spatial heterogeneity of the camphor layer at the air/water interface may play an important role in this mode-switching.