A hybrid structure, including an isotypic p-lnP-p-In0.53Ga0.47As heterojunction and a Pd-p-InP diode, is grown. The current-voltage and capacity-voltage characteristics, the spectral photosensitivity, and the dependence of the photocurrent on bias and magnetic field are investigated. It is shown that photosensitivity is virtually the same at the two main maxima and constitutes Iph equals 6*10-2 A/W for (lambda) max equals 0.90 micrometer and Iph equals (2-4)* 10-2 A/W for (lambda) max equals 1.55 micrometer. The photo-emf at (lambda) equals 0.90 micrometer under the influence of the gas mixture air +500 ppm H2 increases by factor 10. This increase is virtually instantaneous, the drop-off reaches -3 min. The current transport mechanism is investigated and the explanation of variation of photo-emf (photocurrent), and dark current in H2-atmosphere are presented. Such a hybrid structure is of practical interest for detecting both hydrogen and radiation in the near-IR region of the spectrum. Different types of n(p)-InGaAs diode structures have been an object of multifaceted investigations for a number of years, especially in connection with their possible extensive practical applications. Technical developments have been directed primarily toward optimizing the constriction of p-i-n structures, Schottky diodes, avalanche photodiodes, and heterojunctions for fast photodetectors in the wavelength range 1.3 - 1.6 micrometer. The problem of producing detectors for hydrogen gas and hydrogen-containing gases has occupied a prominent spot for a number of years among possible practical applications of semiconductor diode structures. Among our own published studies of this problem, we call attention to Ref. 7 concerning an InGaAs-based photodetector as hydrogen detector. In this communication we report the results of experimental studies of a hybrid structure based on an isotypic p-InP-p-ln0.53Ga0.47As heterojunction and a Schottky barrier formed by a palladium contact on p-InP.