We produced porous glass fiber reinforced ceramic by mixing clay and crushed waste glass fiber reinforced plastic (GFRP) before firing the mixture. Sprues and runners, which are by-products from the manufacture of plastic merchandise by injection molding, were used as waste GFRP. By observing the ceramic microstructure and examining its strength, it was confirmed that porous ceramic reinforced by glass fiber could be produced. In addition, to examine the environmental suitability of the ceramic, the pH of immersion liquid was measured and acid resistance tests were carried out. The immersion solution of the ceramic was neutral or slightly alkaline, the mass loss of the ceramics in the acid resistance test was small and the reduction in bending strength after the tests was also very small. The ceramic is considered to be environmentally benign. The results suggest that the manufacture of porous glass fiber reinforced ceramic can be an effective means to recycle waste GFRP. It is expected that the ceramic could be used as a construction material because of its lightweight, high strength properties and environmental suitability.