A phenolic foam is made by foaming and curing a foamable phenolic resin composition that comprises a phenolic resin, a blowing agent, an acid catalyst and an inorganic filler. The blowing agent comprises an aliphatic hydrocarbon containing from 1 to 8 carbon atoms and the inorganic filler is at least one selected from a metal hydroxide, a metal oxide, a metal carbonate and a metal powder. The phenolic foam has a pH of 5 or more. The phenolic foam has a higher pH value compared with conventional phenolic foam and reduces corrosion risk when in contact with metallic materials. The phenolic foam maintains excellent long-term stable thermal insulation performance, low water uptake and fire resistance performance and by using a hydrocarbon blowing agent, does not harm the environment as an ozone depleting or global warming material.