A structure for producing cast articles, comprising one or more inorganic particles selected from the group consisting of amorphous and artificial graphites and having an average particle diameter of 80 to 3000 μm, an inorganic fiber and a thermosetting resin and having a gas permeability of 6 to 120, wherein the average particle diameter of the inorganic particles such as inorganic particle A can be measured according to the following methods: the inorganic particles are firstly subjected to a first method of measurement; if a resultant value is 200 μm or more, the value is used as an average particle diameter, and if not, the inorganic particles are again measured by a second method of measurement; first method of measurement: inorganic particles are measured according to the method specified in Appendix 2 of JIS Z2601 "test method for molding sand," and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the mass accumulation is to be calculated as considering that particles remaining on respective sieves have corresponding "average diameters Dn (μm)" described in Practical Table 2 of JIS Z2601; second method of measurements: inorganic particles are measured with laser diffraction particle size distribution measurement apparatus (LA-920 manufactured by Horiba Ltd.), and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the analysis conditions are as follows: • measurement method: flow method • refractive index: variable according to inorganic particles (see, a manual for LA-920) • dispersing medium: methanol • dispersing method: ultrasonic agitation for three minutes, with a built-in unit • sample concentration: 2 mg/100 cc. one or more inorganic particles selected from the group consisting of amorphous and artificial graphites and having an average particle diameter of 80 to 3000 μm, an inorganic fiber and a thermosetting resin and having a gas permeability of 6 to 120, wherein the average particle diameter of the inorganic particles such as inorganic particle A can be measured according to the following methods: the inorganic particles are firstly subjected to a first method of measurement; if a resultant value is 200 μm or more, the value is used as an average particle diameter, and if not, the inorganic particles are again measured by a second method of measurement; first method of measurement: inorganic particles are measured according to the method specified in Appendix 2 of JIS Z2601 "test method for molding sand," and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the mass accumulation is to be calculated as considering that particles remaining on respective sieves have corresponding "average diameters Dn (μm)" described in Practical Table 2 of JIS Z2601; second method of measurements: inorganic particles are measured with laser diffraction particle size distribution measurement apparatus (LA-920 manufactured by Horiba Ltd.), and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the analysis conditions are as follows: • measurement method: flow method • refractive index: variable according to inorganic particles (see, a manual for LA-920) • dispersing medium: methanol • dispersing method: ultrasonic agitation for three minutes, with a built-in unit • sample concentration: 2 mg/100 cc. the inorganic particles are firstly subjected to a first method of measurement; if a resultant value is 200 μm or more, the value is used as an average particle diameter, and if not, the inorganic particles are again measured by a second method of measurement; first method of measurement: inorganic particles are measured according to the method specified in Appendix 2 of JIS Z2601 "test method for molding sand," and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the mass accumulation is to be calculated as considering that particles remaining on respective sieves have corresponding "average diameters Dn (μm)" described in Practical Table 2 of JIS Z2601; second method of measurements: inorganic particles are measured with laser diffraction particle size distribution measurement apparatus (LA-920 manufactured by Horiba Ltd.), and a diameter at which a mass accumulation is 50% is set to an average particle diameter; the analysis conditions are as follows: • measurement method: flow method • refractive index: variable according to inorganic particles (see, a manual for LA-920) • dispersing medium: methanol • dispersing method: ultrasonic agitation for three minutes, with a built-in unit • sample concentration: 2 mg/100 cc. • measurement method: flow method • refractive index: variable according to inorganic particles (see, a manual for LA-920) • dispersing medium: methanol • dispersing method: ultrasonic agitation for three minutes, with a built-in unit • sample concentration: 2 mg/100 cc.