To provide a filter for an evaporative humidifier or a cold air device and its manufacturing method, for improving water retentivity, reducing running costs by reducing the water supply amount and improving humidifying or cooling efficiency.

In this filter 10 of the evaporative humidifier 50 for humidifying the air by evaporating the moisture supplied to the filter by allowing the air to pass through the air-permeable filter, pile 17 for retaining the supplied moisture 27 is planted on at least a part of a base material 15, thus the evaporating efficiency of the supplied moisture is improved, and humidifying efficiency is improved.