In this contribution we present our new photometric search for high-z galaxies hosting Population III (PopIII) stars based on deep intermediate-band imaging observations, by using Supreme-Cam on the Subaru Telescope. By combining our new data with the existing broad-band and narrow-band data in the target field, we searched for galaxies which emit strongly both in Lyα and in Heiiλ1640 (“dual emitters”) that are promising candidates for PopIII-hosting galaxies, at 4 ≲ z ≲ 5. Although we found 10 “dual emitters”, most of them turn out to be [Oii]-[Oiii] dual emitters or Hβ-Hα dual emitters at z < 1, as inferred from their broad-band colors and from the ratio of the equivalent widths. No convincing candidate of Lyα-Heii dual emitter with SFRPopIII ≳ 2M⊙ yr−1 was found. This result disfavors low feedback models for PopIII star clusters, and implies an upper limit of the PopIII SFR density of SFRDPopIII < 5 × 10−6M⊙ yr−1 Mpc−3. This new selection method to search for PopIII-hosting galaxies should be useful in future surveys for the first observational detection of PopIII-hosting galaxies at high redshift.