We demonstrate an environmentally stable femtosecond laser for industrial application based on all polarization-maintaining Yb-doped laser and experimentally explore the effect of the net cavity dispersion (NCD) on output characteristics. The oscillator emits pulses with 5.1 ps and a 23 nm spectral bandwidth, then the pulse is compressed to 88 fs. The instabilities over 120 h gives 0.32% relative root mean square noise, indicating high stability of the pulse laser. With effective regulation of NCD, we obtained the maximum spectral bandwidth of 27 nm. Such broadband oscillator with compact all-fiber configurations provide extremely high stability should be very attractive for long-term industrial application.