New N-phenylpyrazole derivatives of the formula: ##STR1## (wherein R.sup.12 represents a chlorine atom, R.sup.13 represents a hydrogen, fluorine or chlorine atom, R.sup.14 represents a hydrogen or fluorine atom and R.sup.15 represents a hydrogen, fluorine or chlorine atom, with the proviso that when R.sup.14 represents a fluorine atom, R.sup.15 represents a fluorine or chlorine atom, or R.sup.12, R.sup.13 and R.sup.15 each represents a fluorine atom and R.sup.14 represents a hydrogen or fluorine atom) possess useful herbicidal properties.