The objective of this study is to design a laboratory experiment to explore the effect of ambiguity on a subject’s search behavior in a finite-horizon sequential search model. In so doing, we employ a strategy to observe the potential trend of reservation points that is usually unobserved. We observe that subjects behaving consistently across treatments reduce their reservation points in the face of ambiguity over point distribution. Our result is consistent with the theoretical implication obtained by Nishimura and Ozaki (Journal of Economic Theory 2004).