The 24 time-resolved spectra of Mrk 421 obtained through Fermi-LAT observations in the 0.1–1000 GeV band. The first 18 spectra were simultaneously obtained with the archived TeV observations, and they are consistent with the data presented in Figure 6. The three panels in the second row from the bottom correspond to the three lowest-flux points in panel (a) of Figure 2, while the three panels in the first row from the bottom correspond to the three highest-flux points in panel (a) of Figure 2. If TS < 9, an upper limit (inverted triangles) is given for that energy bin. The black solid lines and gray dashed lines represent the spectral fitting results and the corresponding 1σ uncertainties, respectively.