Aim: The study aims to find an answer to the question of whether and how the economic indicators in the industrial processing, construction, trade, and services sectors reflect changes in the market size related to investments and working capital loans for micro-enterprises. Methods: The study used data on investment and working capital loans and data on economic conditions. Monthly data for the years 2019–2021, covering the period of the COVID-19 pandemic, were used for the analyses. The estimation of dynamic models was carried out using the Generalized Method of Moments (GMM). Results: The conducted research showed that economic factors play a significant role in shaping the demand for investment and working capital loans in the micro-enterprise sector, but the impact of the economic situation was more significant in the case of investment loans than working capital loans. In periods of economic prosperity, micro-enterprises are more likely to take out investment loans than in periods of economic downturn. Micro-enterprises’ propensity to take out working capital loans is more dependent on their current situation and expectations regarding the demand for products and services. Conclusions: The research revealed differences in the characteristics of the factors significantly influencing the demand for credit, depending on the sector to which the indicator is concerned. The research shows that access to external financing is crucial for the functioning, survival, and expansion of micro, small, and medium-sized enterprises. The research fills the literature gap by showing how the economic situation in individual industries affects the credit market for the micro-enterprises sector.