To provide a method and apparatus for converting a high-water- content organic waste into a powder fuel whereby water can be removed from a high-water-content organic waste; the odor generated in the water removal step can be eliminated before exhausting air; and a powder fuel having such a high heat energy as not to generate dioxins when burned can be yielded.

This method comprises removing water from a high-water- content organic waste with a dryer B, mixing the resultant dried organic waste with suitable amounts of a water-soluble thermoplastic resin and a heat generation assistant material having a high calorific value with a mixer D, kneading the resultant powder fuel raw material under heating and pressure with an extruder E, and crushing the resultant short-cylindrical combustible raw material into a fine powder with crushers F and H, giving the objective powder fuel.