A method of producing a green bonded compact, the green bonded compact comprising: a porous plate-like green substrate having hole portions or recessed portions, the substrate having at least one bonding surface, the green substrate being obtained by forming a slurry containing a first inorganic powder, a dispersion medium, and a binder into a compact, followed by solidification; and a green sheet which is bonded to each bonding surface of the green substrate and is thinner than the green substrate, the green sheet being obtained by forming a slurry containing a second inorganic powder having one of a different composition and a different microstructure from that of the first inorganic powder, a dispersion medium, and a binder into a compact, followed by solidification, the method comprising: a first step of forming a layer of a paste for bonding containing a dispersion medium and a binder on a bonding surface of the green sheet, wherein the dispersion medium contained in the paste for bonding does not dissolve the binder contained in the green substrate, does not dissolve the binder contained in the green sheet, and does dissolve the binder contained in the paste for bonding; a second step of bringing the bonding surface of the green sheet on which the paste layer is formed into contact with the bonding surface of the green substrate under normal temperature while maintaining a state in which the paste layer is wet, a press pressure being applied when the bonding surface of the green sheet is brought into contact with the bonding surface of the green substrate, that press pressure being 0.05 kgf/cm 2 or more and 0.5 kgf/cm 2 or less; and a third step of the pores in the green substrate absorbing the dispersion medium in the paste layer by capillary action under normal temperature to dry the paste layer, thereby bonding the green substrate and the green sheet. a porous plate-like green substrate having hole portions or recessed portions, the substrate having at least one bonding surface, the green substrate being obtained by forming a slurry containing a first inorganic powder, a dispersion medium, and a binder into a compact, followed by solidification; and a green sheet which is bonded to each bonding surface of the green substrate and is thinner than the green substrate, the green sheet being obtained by forming a slurry containing a second inorganic powder having one of a different composition and a different microstructure from that of the first inorganic powder, a dispersion medium, and a binder into a compact, followed by solidification, the method comprising: a first step of forming a layer of a paste for bonding containing a dispersion medium and a binder on a bonding surface of the green sheet, wherein the dispersion medium contained in the paste for bonding does not dissolve the binder contained in the green substrate, does not dissolve the binder contained in the green sheet, and does dissolve the binder contained in the paste for bonding; a second step of bringing the bonding surface of the green sheet on which the paste layer is formed into contact with the bonding surface of the green substrate under normal temperature while maintaining a state in which the paste layer is wet, a press pressure being applied when the bonding surface of the green sheet is brought into contact with the bonding surface of the green substrate, that press pressure being 0.05 kgf/cm 2 or more and 0.5 kgf/cm 2 or less; and a third step of the pores in the green substrate absorbing the dispersion medium in the paste layer by capillary action under normal temperature to dry the paste layer, thereby bonding the green substrate and the green sheet. a first step of forming a layer of a paste for bonding containing a dispersion medium and a binder on a bonding surface of the green sheet, wherein the dispersion medium contained in the paste for bonding does not dissolve the binder contained in the green substrate, does not dissolve the binder contained in the green sheet, and does dissolve the binder contained in the paste for bonding; a second step of bringing the bonding surface of the green sheet on which the paste layer is formed into contact with the bonding surface of the green substrate under normal temperature while maintaining a state in which the paste layer is wet, a press pressure being applied when the bonding surface of the green sheet is brought into contact with the bonding surface of the green substrate, that press pressure being 0.05 kgf/cm 2 or more and 0.5 kgf/cm 2 or less; and a third step of the pores in the green substrate absorbing the dispersion medium in the paste layer by capillary action under normal temperature to dry the paste layer, thereby bonding the green substrate and the green sheet.