Enzymatic degradation of polyester films by a cutinase-like enzyme from Pseudozyma antarctica JCM10317 (PaE) was analyzed by surface plasmon resonance (SPR). The adsorption of PaE and the degradation rate for polyester films were quantitatively monitored by a positive and negative SPR signal shifts, respectively. The decrease in SPR signal and the erosion depth of amorphous poly(L-lactide) (a-PLLA) film measured by atomic force microscopy (AFM) had a linear relationship, and the weight loss was estimated from the AFM data combined with a density of a-PLLA film. Furthermore, SPR sensorgrams for various polyester films showed that degradation rate of poly(ε-caprolactone) and poly(butylene succinate-co-adipate) which contain C6 units was higher than that of other polyesters such as poly(butylene succinate) and a-PLLA. These results suggest that C6 is the preferred chain length as substrates for PaE.