  We have studied the temperature dependence of the photoemission spectra of
Pr$_{1-x}$Ca$_x$MnO$_3$ (PCMO) with $x=0.25$, 0.3 and 0.5. For $x=0.3$ and 0.5,
we observed a gap in the low-temperature CE-type charge-ordered (CO) phase and
a pseudogap with a finite intensity at the Fermi level ($E_F$) in the
high-temperature paramagnetic insulating (PI) phase. Within the CO phase, the
spectral intensity near $E_F$ gradually increased with temperature. These
observations are consistent with the results of Monte Carlo simulations on a
model including charge ordering and ferromagnetic fluctuations [H. Aliaga {\it
et al.} Phys. Rev. B {\bf 68}, 104405 (2003)]. For $x=0.25$, on the other hand,
little temperature dependence was observed within the low-temperature
ferromagnetic insulating (FI) phase and the intensity at $E_F$ remained low in
the high-temperature PI phase. We attribute the difference in the temperature
dependence near $E_F$ between the CO and FI phases to the different correlation
lengths of orbital order between both phases. Furthermore, we observed a
chemical potential shift with temperature due to the opening of the gap in the
FI and CO phases. The doping dependent chemical potential shift was recovered
at low temperatures, corresponding to the disappearance of the doping dependent
change of the modulation wave vector. Spectral weight transfer with hole
concentration was clearly observed at high temperatures but was suppressed at
low temperatures. We attribute this observation to the fixed periodicity with
hole doping in PCMO at low temperatures.
