Transmission spectra of ZnTe‐ZnSe strained‐layer superlattices grown on GaAs (001) have been measured for the first time and step‐like optical‐absorption spectra between conduction and valence subbands have been observed. The GaAs substrates with a narrower band gap than the superlattices were partially removed by a chemical etching method. For the ZnTe‐ZnSe superlattices with a type II band structure, the transmission spectra provide a powerful tool for determining the effective band gap and band offset, because the spatial indirect transition of separately confined electrons and holes is very weak and therefore difficult to observe in photoluminescence measurements. The absorption thresholds observed in the transmission spectra agree very well with the exciton emissions that appeared in photoluminescence data.