We present results of our intermediate-band optical imaging survey for high-z Ly{alpha} emitters (LAEs) using the prime focus camera, Suprime-Cam, on the 8.2m Subaru telescope. In our survey, we used eleven filters: four broad-band filters (B, R_C_, i', and z') and seven intermediate-band filters covering from 500nm to 720nm. We call this imaging program the Mahoroba-11. The seven intermediate-band filters were selected from a series of IA filters, which is the Suprime-Cam intermediate-band filter system, whose spectral resolution is R=23. Our survey was made in a 34'x27' sky area in the Subaru XMM-Newton Deep Survey Field. We found 409 IA-excess objects, which provided us with a large photometric sample of strong emission-line objects. Applying the photometric redshift method to this sample, we obtained a new sample of 198 LAE candidates at 3<z<5. We found no evidence for evolutions of the number density and the star-formation rate density (SFRD) for LAEs with logL(Ly{alpha})(erg/s)>42.67 between z~3 and z~5.