To provide a method of extracting effective ingredients contributing to antibacterial and antioxidant activities effectively from bamboo plants and an antibacterial agent and an antioxidant containing the bamboo extract obtained by the method as an effective ingredient.

The method uses a bamboo plant, preferably Phyllostachys pubescens, more preferably the epidermis of the stem of P. pubescens. The method has (1) a process of treating the plant with steam at 3-7 kg/cm2 and 120-180°C in the presence of steam, (2) a process of cooling the steam-treated product and (3) a process of extracting the cooled product with an extracting solvent containing a 1-4C alcohol, preferably ethanol or an ethanol/water mixture solution. An antibacterial agent and an antioxidant containing the bamboo extract are also provided.