Provided are a film having an excellent balance between heat seal strength and opening strength, a method of producing the film, and a bag obtained by heat-sealing the film. According to the present invention, there is provided a film containing a resin, wherein a resin density of the film is 860 kg/m3 or more and less than 900 kg/m3, and on at least one surface of the film, an arithmetic mean height Sa satisfies the following Expression [1]:

0.10 μm≤Sa≤0.50 μm  [1], and



a minimum autocorrelation length Sal satisfies the following Expression [2]:

0.2 μm≤Sal≤10.4 μm  [2].